A NixOS desktop you can install and look after through a graphical interface.
Sekka brings together Genkan, a graphical installer; Aizome, its own desktop; Tatami, a keyboard-driven tiling desktop; and Yukimi, an app for managing software and system updates. It uses Determinate Nix and lets you choose Aizome, Plasma, GNOME, Tatami, vanilla Hyprland, or Xfce—or install several and switch at login.
Sekka is an early, experimental project. It is not ready to be your dependable everyday operating system. Try it in a disposable virtual machine or on a spare computer with nothing you need to keep.
- Installation erases a whole disk. There is no dual-boot setup, manual partitioning, or option to preserve an existing operating system. Keep backups elsewhere.
- RAID/LVM setup and offline installation are not implemented. An internet connection is required.
- Hardware coverage is limited. Beyond its automated tests in virtual machines, Sekka runs on two laptops: it is in daily use on a Lenovo ThinkPad X1 Carbon Gen 14 with Intel graphics, external displays included, and tested by hand on an Acer Predator Helios Neo 14 with an NVIDIA GeForce RTX 4060 Laptop GPU and Intel graphics, switched with PRIME. That cannot establish that your Wi-Fi, graphics, sleep, or external displays work. Secure Boot is not a supported installation path. The current image targets x86_64 PCs; there is no ARM image.
- Updates and recovery are still being exercised. NixOS generations help you return to an earlier system, but they are not backups of your documents. Btrfs is available without automatic filesystem snapshots.
- There is no production release or support promise. Nightly images are previews, not a release you can rely on: their automated checks run in virtual machines, and a nightly may not have been tried on hardware yet. Older screenshots and test reports are not proof of a tested Sekka release.
If you need a system you can rely on today, wait before installing Sekka.
Images below link to their original, full-resolution PNGs, captured with a scale of 2, at twice the density of the layout. Desktops are shown whole, and each application on its own, cropped to its window. Nothing is upscaled. They come from disposable test VMs built from Sekka's own modules, not from an installed release; see screenshot provenance.
Choose your disk, account, desktop, applications, and location. Review everything before confirming erasure. Genkan prepares the system while you review it, then copies the prepared system to disk.
Genkan's window in preview mode, with sample data, on Sekka's Plasma session.
You can enable LUKS2 disk encryption on the disk page and choose a separate passphrase to unlock the system at startup. The system, personal files and optional swap are encrypted; boot files remain unencrypted. It works with ext4, Btrfs or XFS, using UEFI or legacy BIOS. Encryption is off by default. Remember the disk passphrase: changing your login password does not change it, and Genkan cannot recover it. TRIM is enabled through encryption to let SSDs reclaim space; this reveals which disk blocks are unused. Encrypted installation has not been validated on physical hardware.
Installed systems start behind Sekka's boot splash: the crest on the night ground, with a thin rail that fills as the computer starts, and "Restarting" or "Shutting down" when it stops. Press Esc at any time to see the boot messages, and Esc again to go back; after 15 seconds the splash reminds you. On an encrypted system you type the disk passphrase into the splash, which points out Caps Lock; one passphrase opens both the system and its swap. The splash has been tested in virtual machines, not yet on physical hardware.
The optional GitHub step can import your public SSH keys and set your Git identity. You can also carry your live session's Wi-Fi connections into the installed system.
Choose fish among the applications, here or later in Yukimi, and your terminals open in the fish shell set up as Omarchy sets it up: Omarchy's Starship prompt, vi keys, ls as eza, a cd that falls back to zoxide, and fzf searches of your history (Ctrl + R), files (Ctrl + Alt + F), and Git log and status (Ctrl + Alt + L, Ctrl + Alt + S). Bash stays your login shell and runs scripts. Functions in your own ~/.config/fish and a ~/.config/starship.toml replace Omarchy's. Some of Omarchy's shortcuts call tools fish doesn't bring, such as tmux, ImageMagick, or ffmpeg, and iso2sd and try depend on Omarchy itself, so they don't work.
Programs built for other Linux distributions start as they would there. Editors and tools that download their own programs work without extra setup: Zed's language servers, debugger and AI agents, for example. These downloaded programs find the common libraries: the C and C++ runtimes, zlib, OpenSSL, curl, systemd and a few more. One that needs others, such as most graphical programs, still won't start, and neither will a script that asks for /bin/bash.
Aizome 藍染 is the desktop Sekka is made for, and the installer's preselected choice. It is written from the compositor up in Rust, on Sidestep's native toolkit, and takes its ideas from Haiku, NeXTSTEP and IRIX:
- Every window wears a tab only as wide as its title. Drop one tab on another and the windows stack into a group, from any apps; slide a tab along the top edge with Shift.
- One menu bar shows the focused app's menus. Super + right-click anywhere opens the whole menu at the pointer, and any menu tears off into a palette.
- Super + Space opens the command palette: every command in the focused app's menus, with its shortcut taught back to you, and windows, files, apps, settings and arithmetic.
- The Toolchest launches apps and places, the Deskbar lists each app with its windows and files its notifications beneath it, and Desks keep work apart (Super + Ctrl + ↑ shows them all).
- Super is the command key in every app (Super + C, Super + V), and foot opens in fish.
It comes with its own apps: Settei (Settings), Yukimi, Hako (Files), Sumi (Text Editor), Fusen (Notes), Koyomi (Calendar), Tokei (Clock), Soroban (Calculator), Tenki (Weather), Tansu (Disks), Kura (Disk Usage), Myaku (Activity) and Shashin (Images). Aizome is new, and so far it has run only in virtual machines. See its repository for what is done and what isn't.
Aizome in a disposable NixOS test VM, rendering in software.
Tatami combines Hyprland with a compact bar, searchable application launcher and menus, notifications, display settings, and keyboard shortcuts. It takes inspiration from Omarchy and adapts the experience to NixOS.
Choose a wallpaper under Style › Background. Style › Background settings lets you fill, fit, stretch, center or tile it, or use a solid color, with separate choices for each display. Wallpapers keep their original resolution; your display settings control any cropping.
For long downloads, builds, or overnight work, turn on Keep Awake using the coffee cup in the bar or Super + Ctrl + I. It prevents sleep, automatic screen locking, and lid-close sleep until you turn it off, and remembers your choice at your next login. You can still lock the screen yourself. A red coffee cup means protection could not be verified and needs attention.
To see what is using your computer, open Activity with Super + Ctrl + T. Each application shows with all its processes together, and you can sort them by processor, memory, estimated energy, graphics or disk use. Select one to watch everything about it change, or quit one that misbehaves. Its energy figures are estimates shared out from the processor's and graphics card's meters; the window says what it can and can't measure.
Laptop displays behave the way a Mac's do. Close the lid with an external display connected and the built-in display turns off, its windows move to the other screen, and the laptop keeps running; open the lid and the built-in display comes back where you arranged it. Unplug the last external display and the built-in display turns on. A display you turn off in Displays (Super + Ctrl + D) stays off whenever you reconnect the same displays, until you turn it on again or log in again. If a display change leaves a window off screen, Tatami brings it back, and Super + Ctrl + D always brings the Displays window to the screen you are using.
Some differences remain. Unlike a Mac, the laptop also stays awake with its lid closed while docked on battery power. It goes to sleep when you close the lid with no other display connected, unless Keep Awake is on (then the built-in screen turns off). Lid handling and docking are in daily use on the ThinkPad X1 Carbon Gen 14 with external displays, and virtual-machine tests with simulated displays and a simulated lid guard them between changes.
Sekka also enables USB keyboard and mouse wake paths, including their parent hubs. Waking from an intentional suspend still depends on the hardware and firmware; try a key or mouse button if mouse movement does not wake it.
See what's installed and why, find software, check for updates, return to an earlier generation, and free up store space. Everyday changes do not require editing Nix configuration by hand.
Current application in Tatami, in a disposable NixOS test VM.
Plasma is the default live desktop. GNOME and Xfce are available too. Multiple installed desktops share your account and one login screen: Aizome's own when Aizome is installed, listing every desktop you chose, and GDM when GNOME is, since GNOME locks its screen only under GDM (calamares.loginScreen chooses otherwise).
There is no release yet, only nightly ISOs. An ISO for x86_64 PCs is published only after that exact image has been installed and used in virtual machines: installing, booting the installed system, logging in and using its desktops. That doesn't happen every night, so the newest ISO can be older than the newest update, and an installation catches up with its first update. Each published ISO joins the last seven on sekka.computer/download, with its checksum and the source revision it came from. A nightly may not have been tried on hardware before it is published. Versioned releases will be prereleases on the Releases page. Do not mistake GitHub's “Source code” archives for bootable images.
To put a nightly on a USB drive, Kakehashi lists them, downloads and checks the one you pick, writes it, and reads every byte back, on Linux, macOS or Windows. On Sekka, install it from Yukimi → Discover. Kakehashi is new: so far it has written only virtual drives, and its macOS and Windows builds are GitHub workflow artifacts. Any tool that writes a raw disk image also works.
To build an image yourself, see DEVELOPERS.md. The image starts a live Plasma session with Genkan. The boot menu also offers an older kernel and an Xfce software-rendering recovery session. Check the live desktop on your hardware before considering installation.
Genkan currently offers ext4, Btrfs, or XFS, with UEFI or legacy BIOS boot. Optional RAM-sized swap and system tuning are enabled by default and can be switched off. Proprietary software is allowed by default with an opt-out; redistributable firmware may still be proprietary. The configured NVIDIA driver targets Turing and newer GPUs.
Native 4 KiB sector disks require booting the installation media in UEFI mode. Legacy BIOS installation requires 512-byte logical sectors, including 512e disks.
Open Yukimi → Updates → Update to get Sekka's newest nightly. It brings NixOS, the applications and the AI tools at the versions that nightly built and tested, and a nightly reaches you only once everything it needs is ready to download. An update never compiles software on your computer, except NVIDIA's driver, which is built for your kernel in a few minutes whenever either changes. If space runs short, Yukimi stops before the disk fills up and changes nothing. To update Sekka from a terminal, run:
sekka-updateEnter your administrator password when asked. Sekka downloads the update, builds your system, and applies changes safely. When a restart or sign-out is needed, Yukimi shows one completion message with a button to finish when you are ready. A restart also finishes desktop changes; you will not be asked to restart again for that same prepared update. Once preparation finishes, Yukimi can be closed: the computer starts the prepared system on its next boot. It never restarts or signs you out automatically. Adding or removing a desktop doesn't make an update wait for a restart; the login screen lists the change after your next one. An update that changes how the login screen starts a desktop still waits, since until then the login screen would start its previous version. Your account, installed applications, hardware configuration, and desktop choices stay in place. Previous generations remain available in Yukimi's History and the boot menu.
If your installation predates this command (including the original graphical installer builds), run this once:
nix run github:bitemyapp/sekka/nightly#updateThis also moves supported older installations from the separate Calamares, Tatami, and Yukimi repositories to Sekka. After restarting, the command and button above are available. If the build fails or you cancel before activation, the updater restores the configuration files it changed.
The terminal command and Yukimi's Update button do the same. Sources you have
pointed somewhere of your own keep their own rows and update separately, and
may need building. Run sekka-update --status to check whether anything
remains to be applied.
To get changes before the nightly does, turn on Early updates in
Yukimi's Updates page (in Aizome; in the other desktops, follow main from
the Sekka row's branch button), or run sekka-update --early. Updates then
follow Sekka's main branch as soon as changes are merged, before the
nightly checks run, and anything the binary cache doesn't have yet builds on
your computer. sekka-update --nightly goes back.
Which desktops are installed, which one starts by default, and the login
screen can be changed after installing too: in Aizome's Yukimi →
Desktops, or with sekka-update --choose, such as
sekka-update --choose calamares.loginScreen=aizome. Yukimi asks for your
password, builds the new system, and offers a restart when the change needs
one, as an update does.
Please open an issue with what you tried, what happened, and the image version or source revision. Hardware details help with boot and display problems. Review logs for personal information before attaching them.
To work on the distro, start with DEVELOPERS.md. Tatami and Yukimi can also be used independently on NixOS through Sekka's individual modules.
Sekka builds on NixOS, Determinate Nix, and many other free-software projects. Genkan originated as the NixOS-focused Rust implementation in our Calamares fork. Tatami is inspired by Omarchy. Sekka is not an official NixOS, Determinate Systems, Calamares, or Omarchy product.
Components retain their own licenses and attribution: Genkan is GPL-3.0-or-later; Tatami and Yukimi code is MIT OR Apache-2.0, with separately attributed configuration and artwork. See NOTICE, component provenance, and the license files in each component directory.